Control means for vehicle head lamp to energize low beam when head lamp switch is closed



7, 1967 w. D. SUTHERLAND ETAL ,303,382 CONTROL MEANS FOR VEHICLE HEAD LAMP TO ENERGIZE LOW BEAM WHEN HEAD LAMP SWITCH IS CLOSED Filed May 19, 1964 I5 57 41 :5; OT gig- 7 48 46 55 5 6 I 54 F/GB.

CONTROL MEANS FOR VEHICLE HEAD LAMP T ENERGIZE LOW BEAM WHEN HEAD LAMP SWITCH IS CLOSED William Drummond Sutherland, Isleworth, Middlesex, Albert Victor Waters, Greenford, Middlesex, and Barry John Kendall, Hall Green, Birmingham, England, assignors to Joseph Lucas (Industries) Limited, Birmingham, England Filed May 19, 1964, Ser. No. 368,599 Claims priority, application Great Britain, Mar. 31, 1964, 13,307/64, 13,308/64 3 Claims. (Cl. 315-83) This invention relates to control means for vehicle head lamps of the kind having a main filament which when energized produces the main beam of the head lamps, a secondary filament which when energized produces a dipped beam, and a dip switch for controlling flow of current to the filaments when the vehicle head lamp switch is closed.

According to the invention, a vehicle head lamp lighting system of the kind specified includes relay means operable to ensure that when the head lamps of the vehicle are first switched on the secondary filament only is energized irrespective of the position of the dip switch, but once the dip switch has been actuated it determines which filament is energized in accordance with the position of the dip switch.

In the accompanying drawings, FIGURES 1 to 3 respectively are circuit diagrams illustrating three examples of the invention.

Referring to FIGURE 1, there is provided a main filament 4 which when energized produces the main beam of the lamp, and a secondary filament 5 which when energized produces a dipped beam. One end of each filament is connected to a terminal 6, preferably constituted by an earthed part of the vehicle, whilst the other ends of the main and secondary filaments 4, 5 respectively are connected in use to terminals 7, 8 of a control means for the system.

The terminal 7 is connected to one end of a main coil 9 of a relay through parallel paths containing respectively a resistor 10, and a normally open contact 11 operable by energization of the coil 9. The other end of the coil 9 is connected through the vehicle head lamp switch 12 to a terminal 13, the terminals 6, 13 being connected in use to a battery or other source of direct current. The terminal 8 is connected to the terminal 13 through a normally closed contact 14 in series with the switch 12, the contact 14 being operable by energization of the coil 9.

There is also provided a dip switch 15 having a movable contact connected to the terminal 13 through the switch 12 and movable by the driver between a first position in which it short-circuits the coil 9 and a second position (shown in broken lines) in which it short-circuits the contact 14. Moreover, the relay includes a sec-0nd coil 16 having one end connected to the terminal 6 and its other end connected to the terminal 13 through the switch 12, and preferably a warning lamp 17 is connected in parallel with the filament 4 to indicate when the latter is energized.

When the switch 12 is closed, the coil 16 is energized irrespective of the position of the switch 15. However, the coil 16 is not capable of operating contacts 11, 14 by itself, but is capable of maintaining the cont-acts 11, 14 in their operated condition.

Assuming that when the switch 12 is closed the dip switch 15 is in the position shown in broken lines, then on closing of the switch 12 the filament 5 will be energized directly through the switch 15 and the contact 14 in parallel. At the same time a current will flow through the coil 9 and resistor to the filament 4, and the resistance United States Patent 0 3,303,382 Patented Feb. 7, 1967 in the circuit to the filament 4 is so chosen that this current is sufiicient to energize the coil 9 but insufficient to energize the filament 4.

Energization of the relay operates both pairs of contacts 11, 14 and thereafter these contacts are maintained in their alternative positions by the coil 16 until the switch 12 is re-opened. When the contacts 14 open, the filament 5 is still energized through the switch 15. Closing of contact 11 short-circuits the resistor 10, but the resistance of the coil 9 is sufiicient to prevent the filament 4 from being energized. The first actuation of the switch 15 shortcircuits the coil 9, but the coil 16 maintains the relay energized and the filament 4 is energized through the contact 11. Further successive movements of the switch 15 will energize the secondary and main filaments 5, 4 alternately.

Assuming that when the switch 12 is closed the dip switch 15 is in the position shown in full lines, the coil 9 is short-circuited and the current flowing to the filament 4 is limited by the resistor 10 to a value such that the filament 4 is not illuminated. However, the filament 5 is energized through the contact 14. In this case the first movement of the switch 15 maintains the filament 5 energized, and thereafter the operation is as above described.

By a construction as above described, therefore, closing of the switch 12 results in the production of a dipped beam irrespective of the initial position of the switch 15, thereby avoiding the risk of dazzling oncoming trafiic inadvertantly. It will be understood that in practice where two head lamps are provided the main and secondary filaments of the respective head lamps will be connected in parallel.

Referring now to FIGURE 2, there are provided terminals 21, 22 which in use are connected to the battery of a vehicle so as to be positive and negative respectively. The terminal 22 is connected through the head lamp switch 23 of the vehicle to a make-before-break relay contact 24 which in its normal position contacts a first contact piece 25 connected to the terminal 21 through the dipped beam filament 26. In its energized position, the relay contact 24 contacts a second contact piece 27 which is connected to the terminal 21 through the coil 28 of the relay, and is further connected to the movable contact of a dip switch 29 which in its dipped position shown in full lines is connected to the terminal 21 through the dipped beam filament 26 and in its full beam position shown in dotted lines is connected to the terminal 21 through the main beam filament 30.

Assuming that the dip switch 29 is in its full beam position when the head lamp switch is closed, the dipped beam filament 26 will be energized through the relay contact 24. The first actuation of the dip switch 29 now completes a circuit through the relay contact 24 and dip switch 29 to energize the relay coil 23, which self-holds because the relay contact 24 is of the make-before-break variety. Energization of the relay coil also completes a circuit to the dip switch through the contact 24, and contact piece 27 and thereafter successive actuations of the dip switch energize the main and dipped beam filaments in turn.

If the dip switch is in its dipped beam position when the head lamp switch is closed, the dipped beam filament 26 is still energized through the relay contact 24 and contact piece 25 initially, but the relay coil is also energized so that successive actuations of the dip switch energize the main and dipped beam filaments in turn.

Referring now to FIGURE 3, there are provided terminals 31, 32 which in use are connected to the positive and negative terminals of the Vehicle battery indicated at B. The terminal 32 is connected through the head lamp switch 33 of the vehicle to the movable contact 34 of a dip switch, this contact being movable alternately into contact with fixed contact pieces 35, 36.

the relay contacts 41, 37 to energize the first relay.

The circuit further includes a first relay having firs-t, second, third and fourth contacts 37, 38, 39, 40 and a second relay having fifth and sixth contacts 41, 42. One end of the coil 43 of the first relay is connected to the terminal 31, whilst its other end is connected to the contact piece 35 through the relay contacts 37, 41 in series. Similarly, one end of the coil 44 of the second relay is connected to the terminal 31 and its other end is connected to the contact piece 36 through the relay contacts 42, 38 in series. The relay contacts 39, 40 are connected to the contact pieces 35, 36 respectively, and normally closed contact pieces 45, 46 respectively. However, when the relay coil 43 is energized they move to positions in contact with contact pieces 47, 48 respectively. The contact pieces .6, 47 are connected to the terminal 31 through the dipped beam filament 49 whilst the contact pieces 45, 48 are connected to the terminal 31 through the main beam filament 50.

In use, assuming that the dip switch has its movable contact 34 in contact with the contact piece 35, then when the head lamp switch 33 is closed current flows through The contact 37, which is of the make-before-break variety, completes a hold-on circuit to the relay coil 43 through the head lamp switch 33, and the contact 38 opens to break the circuit to the relay coil 44. Energization of the relay coil 43 also moves the contacts 39, 49- into contact with contact pieces 47, 48 and so the dipped beam filament is energized by way of the relay contact 397 On actuation of the dip switch, the clipped beam circuit is broken, but a circuit to the main beam filament is completed through the relay contact 40. Thus, successive actuations of the dip switch energize the main and dipped beam filaments in turn, the relay coil 43 remaining energized until the head lamp switch 33 is opened.

Assuming that when the head lamp switch 33 is closed the dip switch is in contact with the contact piece 36, the relay coil 44 is energized. The contact 42 is of the makebeforebreak variety and completes a hold-on circuit through the head lamp switch to the relay coil &4, whilst the contact 41 breaks the circuit to the relay coil 43. The contacts 39, 40 are not moved because the relay coil 43 is not energized, and so the clipped beam filament 49 is energized through the contact 40. When the dip switch is actuated, the main beam filament 50 is energized through the contact 39, and thereafter successive actuations of the dip switch cause the dipped and main beam filaments to be energized in turn. It will thus be appreciated that irrespective of the initial position of the dip switch, the dipped beam filaments will be energized when the head lamp switch is closed, and that the main beam filaments will be enerigized by the first actuation of the dip switch.

Having thus described our invention what we claim as new and desire to secure by Letters Patent is:

1. A vehicle head lamp lighting system comprising first and second terminals which in use are connected to a source of voltage, main and secondary filaments which when energized produce the main and dipped beams respectively, the main and dipped filaments each having one end connected to the first terminal and their other ends connected to third and fourth terminals respectively,

a dip switch having a contact movable between a pair of alternative positions, a head lamp switch through which the movable contact of the dip switch is connected to the second terminal, a resistor, and a relay having first and second coils, a normally open contact and a normally closed contact, the second coil being capable of maintaining the relay energized but incapable of energizing the relay itself, the first coil having one end connected to the second terminal through the head lamp switch and its other end connected to the third terminal through the normally open contact and the resistor in parallel, the normaly closed contact being connected between the fourth and second terminals in series with the head lamp switch, and the second coil being connected between the first and second terminals in series with the head lamp switch, the dip switch serving in its alternative positions to short-circuit the first coil and the normally closed contact respectively, and the resistances of the first coil and'resistor being such that the main filament is only energized. when it is energized through the dip switch and normally open contact in series.

2. A vehicle head lamp lighting system of the kind specified including a relay con-tact in series between the headlamp switch and the dip switch, the coil of the relay being connected between the side of the filaments remote from the dip switch, and a point between the dip switch and relay contact, the relay con-tact being of the makebeforebreak variety and being movable betwen a deenergized position in which it completes a circuit to the secondary filament and an energized position in which it completes a circuit to the dip switch. 1

3. A vehicle headlamp lighting system including a headlamp switch controlling the headlamps of the vehicle, a dip switch through which said headlamps are energized when said headlamp switch is closed, said headlamps including a main filament which is energized when the head lamp switch is closed in one position of the dip switch to produce the main beam of the head lamps, and

a secondary filament which is energized when the headlamp switch is closed in the other position of the dip .switch to produce a dipped beam, first and second relays one or other of which is energized through the dip switch when the head lamp switch is closed depending on the position of the dip switch, each of said relays having a contact which when operated prevents energization of the other relay, and .a further contact which when operated completes a hold-on circuit to its own relay through said head lamp switch, and one of said relays having a further pair of contacts through which the dip switch feeds the main and dipped beam filaments, said further pair of contacts ensuring that the dipped beam filaments are al- Ways energized initially when said head lamp switch is closed.

References Cited by the Examiner UNITED STATES PATENTS 2,910,621 10/1959 Paule 3l582 3,139,555 6/1966 Paule et a1 315-83 X JAMES W. LAWRENCE, Primary Examiner. C. R. CAMPBELL, Assistant Examiner. 

1. A VEHICLE HEAD LAMP LIGHTING SYSTEM COMPRISING FIRST AND SECOND TERMINALS WHICH IN USE ARE CONNECTED TO A SOURCE OF VOLTAGE, MAIN AND SECONDARY FILAMENTS WHICH WHEN ENERGIZED PRODUCE THE MAIN AND DIPPED BEAMS RESPECTIVELY, THE MAIN AND DIPPED FILAMENTS EACH HAVING ONE END CONNECTED TO THE FIRST TERMINAL AND THEIR OTHER ENDS CONNECTED TO THIRD AND FOURTH TERMINALS RESPECTIVELY, A DIP SWITCH HAVING A CONTACT MOVABLE BETWEEN A PAIR OF ALTERNATIVE POSITIONS, A HEAD LAMP SWITCH THROUGH WHICH THE MOVABLE CONTACT OF THE DIP SWITCH IS CONNECTED TO THE SECOND TERMINAL, A RESISTOR, AND A RELAY HAVING FIRST AND SECOND COILS, A NORMALLY OPEN CONTACT AND A NORMALLY CLOSED CONTACT, THE SECOND COIL BEING CAPABLE OF MAINTAINING THE RELAY ENERGIZED BUT INCAPABLE OF ENERGIZING THE RELAY ITSELF, THE FIRST COIL HAVING ONE END CONNECTED TO THE SECOND TERMINAL THROUGH THE HEAD LAMP SWITCH AND ITS OTHER END CONNECTED TO THE THIRD TERMINAL THROUGH THE NORMALLY OPEN CONTACT AND THE RESISTOR IN PARALLEL, THE 